Partial purification and characterization of the bacteriocin produced by Lactobacillus acidophilus YIT 0154

One strain of Lactobacillus acidophilus was found to produce a bacteriocin-like substance in the culture filtrate. The substance was produced in a growth-associated manner, showed heat stability at neutral and acidic pH and exhibited antibacterial activity against various species of Lactobacillus including, L. acidophilus itself. The molecular weight of the substance was in the range of 6.2-9.5 kDa. N-terminal amino acid sequence analysis suggests that the substance may belong to class IIb bacteriocin.